Piston-packing expander.



PISUN PAQKING EXPANDE APPLicmm-l man mem, E916:

GEORGE CHRISTENSON, OF JAMAICA, NEW YORK, ASSIGNOR T0 I-I. W. JQHE-FS-M'NVLLE COMPANY, A CORPORATION OF NEW YORK.

PISTON-PACKING EXPANDER.

Specification of Letters Patent.

Patented tti, 393W.

To all whom t may concern.'

Be it known that I, GEORGE CHRISTENSON, a citizen of the United States of -America, residing at Jamaica, county of Queens, State of New York, have invented certainnew and useful Improvements in Piston-,Backing Expanders, of which the followingis a specification. A My invention relates to devices for expanding flexible packing for pistons such as are used in air brake cylinders, and comprises certain improvements on, or modifications of, the structure shown in my U. S. Patent No. 862,540, dated August 6,1907. The best form of apparatus embodying my present invention now known to me is illustrated in the accompanying sheet of drawings in which* Figure 1 is an axial section of an air brake cylinder and piston with my invention applied thereto, parts being broken away and Fig. 2. is a perspective view of the grooved spring split-ring expander.

Throughout the drawings like reference characters indicate like parts. 1, is a portion of the ordinary air brake cylinder having the head 2, fastened to it by bolts 3. 4, is a piston head; 5, the pistonfollower, and 6,

' one of the' bolts which fasten the head and follower together to form the usual piston structure. r', is the usual form of hollow piston rod used in freight brake/"duipment, set in the piston head 4, and '8, the usual push rod. The usual form of cup leather' packing is shownl in Fig. l, formed of a strip of leather or other iiexible material having the cylindrical outer portion 9, and the inwardly bent ring-shaped inner edge portion l0. e

rfhe foregoing parts are of usual eonstruction except that the piston follower 5, is out away more than usual so as to leave a circumferential tongue 14, projecting therefrom. ...11, Yis a spring split-ring having a groove 13, on its inner surface which ts over the vtongue 14, on the piston follower 5. in Fig. 2 the spring is shown in its normal position when not under tension with its ends 12, 12, slightly separated. 0f course said groove.

when the ring is sprung into position, es shown in Fig. 1, these ends more nearly abut and the elastic reaction of the spring holds' the cylindrical part 9, of the cup leather firmly against the walls of the cylinder. it

the same time, the circumferential tongue 14, on the piston follower iitting somewhat loosely in the groove 13, of the packing ring 11, serves as a guide and retainer for said packing ring during all movements of the assembled parts. i

The advantages of my invention over prior forms of piston packing` expander comprise the broad area of outward pressure exerted on the inner surface of the packing leather A resuiting from the wide face of ring il, the

suit of the pressure of the expander being localized at that point in moet previous stractures.

Having described my invention, i claim l. The combination with the usual i structure and band of flexible packing on, of a spring split-ring expander ar within said packing provided with a rior circumferential groove, and a circ ential projection on the piston structu ting into said groove and adapted tc a guide and retainer for the spring 2. The Combination with the usual head, piston follower, and cup leather Y ing having its inner edge clamped between the two, of a spring split-rimM within the f' v l l n J lindrical portion of the paclanng, said ring having a circumferential groove in its interior surface, and said piston follower ing a circumferential tongue fitting inte GEURGE HRl'STENSlQ'.

Sud 

